Typically, network management systems use deltaTime to normalize counter differences, i.e., to convert counter differences into rates. This variable is defined as the time between the receipt of successive poll responses by the network management system and can be inaccurate if a poll response suffers inordinate delays in the polled agent, the network, or the network management server. This problem can affect the calculation of any reportable rate, such as bytes/second or packets/second. While it has limited impact on average rates over long time periods, inaccuracies are visible to customers in trend reports based on raw poll periods, reports featuring peak utilizations, etc. The situation tends to get worse as the load on the network management server, network, or polled device increases and resources available for processing poll responses are accordingly diminished.